Due to their composition, many cosmetic products are susceptible to act as a culture medium for micro-organisms, and this can possibly cause changes to the cosmetic preparation and constitute a risk to human heath as well. Thus, a cosmetic composition necessarily requires good protection against microbiological contamination. For this reason, a large number of preservatives to inhibit or reduce the microbial population is used.
Most of the systems currently used display incompatibilities with the human skin, such as irritations and allergies and are toxic to human beings as well. On the other hand, it has been demonstrated that cationic surfactants derived from lauric acid and arginine are protective substances against micro-organisms, in particular, the ethyl ester of the lauramide of the arginine monohydrochloride, hereafter referred to as LAE. LAE has the chemical structure of formula (1).

The compound LAE is remarkable for Its activity against different micro-organism, like the bacteria, fungi and yeast which can be present in cosmetic formulations and preparations, and its innocuity for humans.
It was the object of the present invention to provide further preservative systems for cosmetic preparations with in particular the goal of providing systems which comprise smaller amounts of the usual preservatives in view of the risk of lack of tolerance.